Visual disabilities are caused, for example, by cataract, glaucoma, macular degeneration and night blindness. No effective method for medical treatment is available at present for a visually impaired patient having a trouble in the daily life.
A head-mounted display apparatus is proposed as a visual aid display apparatus used by a patient of night blindness, (e.g. Japanese Patent Application Laid-Open No. 7-288754 publication), and amblyomia spectacles or the like are also proposed as a visual aid display apparatus used by a patient of amblyomia (e.g. Japanese Patent Application Laid-Open No. 9-192164 publication).
An apparatus disclosed in the Japanese Patent Application Laid-Open No. 2002-156600 publication is known as a visual display apparatus worn on the face. However, this disclosure fails to propose a technological concept of displaying by compressing the luminance of an inputted image, reducing the luminous intensity or processing the image information captured by an image-capturing apparatus.
The prior art visual aid display apparatus has been designed in a large-sized goggle type that covers the entire face of a patient. This is not very convenient for a patient in leading the daily life. Thus, the problem with this prior art is that a landscape cannot be identified and the observer's eyes cannot be checked by a person providing medical treatment. Further, wearing a prominent apparatus in the daily life will produce a sense of incompatibility with the surrounding.
To assist a visually handicapped person to walk, a proposal has been made of a method wherein an image captured by a TV camera is displayed on a portable CTR. However, this requires assistance of another person carrying a TV camera, and also requires the handicapped person to hold the CRT, with the result that both hands are occupied.
In the prior art, the eye protector used for reducing the sun dazzle of the user absorbs a specific wavelength of e.g. 500 nm or less, and is effective in reducing the dazzle of light to a certain extent. However, since the information of a specific wavelength is completely lost, the color of signals and others cannot be easily identified. This is a problem in the prior art. Further, when sunglasses are worn, it is necessary to prepare many types of glasses having different transmittances and to select an appropriate type in conformity to a particular environment such as outdoors and indoors. The problems are also found in the higher costs in preparing a plurality of glasses and the trouble of having to carry a plurality of glasses and to use them in conformity to the particular environmental requirement.